Replacing imported PA6, PA66, PPA and PBT grades: Material Wizard candidate grades and the verification procedure

When a specification references a specific imported grade and that grade is no longer available, a design engineer needs two things at once: the name of a candidate and the list of what that candidate has to prove. Both are provided below. The tables give a Material Wizard candidate grade by polymer class and reinforcement type — this is the starting point of the comparison, and we provide it the same day. Suitability in a specific assembly is confirmed by checking the distinguishing parameters and by a trial run on your mold. We go through that part of the work together with you.

What a grade name in a specification actually fixes

The entry "PA66 GF30" on a drawing encodes two facts: the base class and the glass fiber mass fraction. Everything else that determines part behavior is not written in the name. The heat stabilization package, lubricant and nucleating agent, melt viscosity matched to wall thickness, moisture condition as delivered — all of that lives in the producer's formulation, not in the label on the bag.

This is why two grades with an identical designation from different producers show different shrinkage and a different processing window. Both, at the same time, honestly comply with the specification entry. Glass-filled polyamide — still called reinforced nylon in everyday shop language — is not an exception here but the typical case.

The practical consequence is short. A candidate is selected by class and reinforcement — that takes minutes. Agreement on the candidate is reached through distinguishing parameters and a trial run — that takes from several days to several weeks depending on how critical the part is.

The procedure: four steps

1. Class and reinforcement. The imported designation is read for base polymer, filler type and fraction, and the presence of flame-retardant or impact modification. This gives you a row in the tables below.
2. Candidate. A Material Wizard grade of the same class and the same reinforcement level. For most positions there is one candidate. Where there are several, the choice is made by viscosity and delivery condition.
3. Check of distinguishing parameters. Density, flexural modulus and strength, elongation at break, melting temperature, deflection temperature under load. A mismatch in this set means the reinforcement level or the base was read incorrectly.
4. Trial run. A first batch on your mold with process parameters and part dimensions recorded. For critical assemblies — with testing of the finished part, not only standard specimens.

Candidate grades by class

The designations in the "Imported reference" column are given for class and reinforcement comparison and have been checked against the producers' public datasheets as of the preparation date. These are third-party trademarks owned by their respective holders. We do not claim formulation identity: a candidate is comparable to the reference by class and reinforcement, and is produced to our own formulation.

PA6, reinforced and modified

PA66, reinforced and modified

PPA and high-temperature polyamides

A clarification saves time for both sides here. Zytel® HTN is a family of series based on different copolymers, not a single grade. The same applies to Amodel® and Grivory® HT. A request for a "Zytel HTN equivalent" without the series number and reinforcement type defines the class but not the assembly. The candidates below are selected by reinforcement and flammability requirement. The copolymer base is agreed once the working temperature and the environment are known.

Long-chain polyamides: PA610, PA612, PA12

This is the case where a like-for-like replacement often turns out more expensive than reconsidering the class. If the specification says PA66, the part works in a humid environment, and the complaint about it is dimensional — a long-chain polyamide solves the problem more precisely than a search for yet another PA66.

PBT

For references such as Ultradur®, Crastin®, Pocan® and Valox®, positions are produced to order: base PBT with 20 to 30 % glass reinforcement, in black and natural, with or without a V-0 requirement. The reason this class is not held as a stock line is typical batch size. PBT is ordered for a specific assembly, not for the shelf. A request stating the reinforcement, the flammability requirement and the monthly volume is handled individually.

Recycled polyamides

When a part is non-structural and its requirement is to carry the load and the price, a recycled stream closes the task at a lower cost than a virgin compound. The Examid® PA6R G and Examid® PA66R G lines are built on a sorted recycled stream. The main unknown here is not the property level but the width of the batch composition — and that is exactly what we document. Moving from a virgin grade to a recycled one is a design decision, not a purchasing decision: it is taken at the stage where the cross-section can still be changed.

Distinguishing parameters: how a candidate is verified

The set below answers one question: does the candidate really belong to the same class and reinforcement level as the reference. Each parameter is taken from the grade's datasheet together with its measurement conditions — without them, two numbers cannot be compared.

For polyamides the specimen state is decisive: dry and conditioned material give different mechanical numbers, so datasheets are compared only in the same state. Comparing a dry number against a conditioned one is a typical source of false alarm during benchmarking.

Limits: when we will say a replacement is not reasonable

• The part carries long-term load at a temperature close to the class limit, and no margin is defined in the specification.
• The assembly goes through an approval in which the material grade is named explicitly, and no document reissue is planned.
• The mold was designed for a specific shrinkage, and there is no budget for rework.
• The annual volume is below the batch size at which compounding makes sense. The more honest answer is then a European grade sourced to order, not a custom compound.

What to agree before series launch

1. Who owns the replacement decision — the owner of the design documentation or the processor, and in which document the decision is recorded.
2. The list of distinguishing parameters with methods, specimen state and limits — based on the table above, narrowed down to the specific assembly.
3. The scope of the trial run: how many cycles, on which mold, which part dimensions and characteristics are measured and by whom.
4. Part criteria, not only material criteria: dimensions after conditioning, breaking force, leak-tightness — what the assembly exists for.
5. The procedure in case of deviation: what counts as a process adjustment note, and what is grounds to return to candidate selection.

Expert review: 5 questions

1. Can a grade be replaced without changing the drawing? If the drawing names a class and a reinforcement level — yes. If it names a trademark — a reissue or an approved-substitution record is needed. That decision belongs to the owner of the design documentation; we provide the data for it.

2. How long does candidate confirmation take? Matching by class and reinforcement — the same day. Checking the distinguishing parameters — against available datasheets, usually days. The trial run on your mold and part measurement depend on mold availability. This is the longest part, and it is convenient to plan the replacement from it.

3. Why are there no property values in the tables? Comparison by a single column of numbers is the most frequent cause of a failed replacement: numbers from different datasheets are taken under different conditions and specimen states. We provide values as a datasheet for a specific grade, with the method and specimen state, because those conditions decide whether two numbers are comparable.

4. Does matching class and reinforcement mean the part will come out the same? No. Matching class and reinforcement means the candidate is chosen correctly as a starting point. Shrinkage, the processing window and weld line behavior are shown only by a trial run on your mold — which is why it is a separate step in the procedure, not a footnote.

5. What if the needed position is not in the tables? Send the imported grade designation and a description of the assembly: temperature, environment, load, wall thickness. We will reconstruct the class and reinforcement from the producer's public datasheet, and then follow the four-step procedure.

Examid® PA6 GF30 — Glass-filled polyamide 6 with 30% glass fiber — the candidate for the most common imported classMatching against the reference by class and reinforcement · verification list for your assemblyRequest delivery terms →

Examid® PA66 GF50 Y — Highly filled polyamide 66 for stiff structural assembliesCandidate for imported PA66 GF50 · datasheet-based parameter verificationRequest delivery terms →

Examid® engineering polyamides — Line hub: unfilled, glass-filled and carbon-filled gradesCandidate selection against an imported reference and a pre-series verification programGo to catalog →

Material Wizard produces and supplies engineering polymers: its own Examid®, Exablend® and Exaflex® compounds and European grades sourced to order. For a request, the imported grade designation and a short description of the assembly are enough: we will return a candidate and a verification list. To buy with delivery across Ukraine or to agree on a replacement program — check with our specialist.